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 * SPDX-License-Identifier: Apache-2.0
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 * The OpenSearch Contributors require contributions made to
 * this file be licensed under the Apache-2.0 license or a
 * compatible open source license.
 */

/*
 * Licensed to Elasticsearch under one or more contributor
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 * this work for additional information regarding copyright
 * ownership. Elasticsearch licenses this file to you under
 * the Apache License, Version 2.0 (the "License"); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
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/*
 * Modifications Copyright OpenSearch Contributors. See
 * GitHub history for details.
 */

package org.opensearch.action.admin.indices.datastream;

import org.opensearch.Version;
import org.opensearch.action.ActionRequestValidationException;
import org.opensearch.action.admin.indices.datastream.DeleteDataStreamAction.Request;
import org.opensearch.cluster.ClusterName;
import org.opensearch.cluster.ClusterState;
import org.opensearch.cluster.SnapshotsInProgress;
import org.opensearch.cluster.metadata.DataStream;
import org.opensearch.cluster.metadata.IndexMetadata;
import org.opensearch.cluster.metadata.Metadata;
import org.opensearch.cluster.metadata.MetadataDeleteIndexService;
import org.opensearch.common.Strings;
import org.opensearch.common.collect.ImmutableOpenMap;
import org.opensearch.common.collect.Tuple;
import org.opensearch.common.io.stream.Writeable;
import org.opensearch.common.settings.Settings;
import org.opensearch.index.Index;
import org.opensearch.snapshots.Snapshot;
import org.opensearch.snapshots.SnapshotId;
import org.opensearch.snapshots.SnapshotInProgressException;
import org.opensearch.test.AbstractWireSerializingTestCase;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

import static org.opensearch.cluster.DataStreamTestHelper.createTimestampField;
import static org.hamcrest.Matchers.containsInAnyOrder;
import static org.hamcrest.Matchers.containsString;
import static org.hamcrest.Matchers.equalTo;
import static org.mockito.Mockito.any;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;

public class DeleteDataStreamRequestTests extends AbstractWireSerializingTestCase<Request> {

    @Override
    protected Writeable.Reader<Request> instanceReader() {
        return Request::new;
    }

    @Override
    protected Request createTestInstance() {
        return new Request(randomArray(1, 3, String[]::new, () -> randomAlphaOfLength(6)));
    }

    public void testValidateRequest() {
        DeleteDataStreamAction.Request req = new DeleteDataStreamAction.Request(new String[] { "my-data-stream" });
        ActionRequestValidationException e = req.validate();
        assertNull(e);
    }

    public void testValidateRequestWithoutName() {
        DeleteDataStreamAction.Request req = new DeleteDataStreamAction.Request(new String[0]);
        ActionRequestValidationException e = req.validate();
        assertNotNull(e);
        assertThat(e.validationErrors().size(), equalTo(1));
        assertThat(e.validationErrors().get(0), containsString("no data stream(s) specified"));
    }

    public void testDeleteDataStream() {
        final String dataStreamName = "my-data-stream";
        final List<String> otherIndices = randomSubsetOf(org.opensearch.common.collect.List.of("foo", "bar", "baz"));
        ClusterState cs = getClusterStateWithDataStreams(
            org.opensearch.common.collect.List.of(new Tuple<>(dataStreamName, 2)),
            otherIndices
        );
        DeleteDataStreamAction.Request req = new DeleteDataStreamAction.Request(new String[] { dataStreamName });
        ClusterState newState = DeleteDataStreamAction.TransportAction.removeDataStream(getMetadataDeleteIndexService(), cs, req);
        assertThat(newState.metadata().dataStreams().size(), equalTo(0));
        assertThat(newState.metadata().indices().size(), equalTo(otherIndices.size()));
        for (String indexName : otherIndices) {
            assertThat(newState.metadata().indices().get(indexName).getIndex().getName(), equalTo(indexName));
        }
    }

    public void testDeleteMultipleDataStreams() {
        String[] dataStreamNames = { "foo", "bar", "baz", "eggplant" };
        ClusterState cs = getClusterStateWithDataStreams(
            org.opensearch.common.collect.List.of(
                new Tuple<>(dataStreamNames[0], randomIntBetween(1, 3)),
                new Tuple<>(dataStreamNames[1], randomIntBetween(1, 3)),
                new Tuple<>(dataStreamNames[2], randomIntBetween(1, 3)),
                new Tuple<>(dataStreamNames[3], randomIntBetween(1, 3))
            ),
            org.opensearch.common.collect.List.of()
        );

        DeleteDataStreamAction.Request req = new DeleteDataStreamAction.Request(new String[] { "ba*", "eggplant" });
        ClusterState newState = DeleteDataStreamAction.TransportAction.removeDataStream(getMetadataDeleteIndexService(), cs, req);
        assertThat(newState.metadata().dataStreams().size(), equalTo(1));
        DataStream remainingDataStream = newState.metadata().dataStreams().get(dataStreamNames[0]);
        assertNotNull(remainingDataStream);
        assertThat(newState.metadata().indices().size(), equalTo(remainingDataStream.getIndices().size()));
        for (Index i : remainingDataStream.getIndices()) {
            assertThat(newState.metadata().indices().get(i.getName()).getIndex(), equalTo(i));
        }
    }

    public void testDeleteSnapshottingDataStream() {
        final String dataStreamName = "my-data-stream1";
        final String dataStreamName2 = "my-data-stream2";
        final List<String> otherIndices = randomSubsetOf(Arrays.asList("foo", "bar", "baz"));

        ClusterState cs = getClusterStateWithDataStreams(
            Arrays.asList(new Tuple<>(dataStreamName, 2), new Tuple<>(dataStreamName2, 2)),
            otherIndices
        );
        SnapshotsInProgress snapshotsInProgress = SnapshotsInProgress.of(
            Arrays.asList(createEntry(dataStreamName, "repo1", false), createEntry(dataStreamName2, "repo2", true))
        );
        ClusterState snapshotCs = ClusterState.builder(cs).putCustom(SnapshotsInProgress.TYPE, snapshotsInProgress).build();

        DeleteDataStreamAction.Request req = new DeleteDataStreamAction.Request(new String[] { dataStreamName });
        SnapshotInProgressException e = expectThrows(
            SnapshotInProgressException.class,
            () -> DeleteDataStreamAction.TransportAction.removeDataStream(getMetadataDeleteIndexService(), snapshotCs, req)
        );

        assertThat(
            e.getMessage(),
            equalTo(
                "Cannot delete data streams that are being snapshotted: [my-data-stream1]. Try again after "
                    + "snapshot finishes or cancel the currently running snapshot."
            )
        );
    }

    private SnapshotsInProgress.Entry createEntry(String dataStreamName, String repo, boolean partial) {
        return new SnapshotsInProgress.Entry(
            new Snapshot(repo, new SnapshotId("", "")),
            false,
            partial,
            SnapshotsInProgress.State.SUCCESS,
            Collections.emptyList(),
            Collections.singletonList(dataStreamName),
            0,
            1,
            ImmutableOpenMap.of(),
            null,
            null,
            null
        );
    }

    public void testDeleteNonexistentDataStream() {
        final String dataStreamName = "my-data-stream";
        String[] dataStreamNames = { "foo", "bar", "baz", "eggplant" };
        ClusterState cs = getClusterStateWithDataStreams(
            org.opensearch.common.collect.List.of(
                new Tuple<>(dataStreamNames[0], randomIntBetween(1, 3)),
                new Tuple<>(dataStreamNames[1], randomIntBetween(1, 3)),
                new Tuple<>(dataStreamNames[2], randomIntBetween(1, 3)),
                new Tuple<>(dataStreamNames[3], randomIntBetween(1, 3))
            ),
            org.opensearch.common.collect.List.of()
        );
        DeleteDataStreamAction.Request req = new DeleteDataStreamAction.Request(new String[] { dataStreamName });
        ClusterState newState = DeleteDataStreamAction.TransportAction.removeDataStream(getMetadataDeleteIndexService(), cs, req);
        assertThat(newState.metadata().dataStreams().size(), equalTo(cs.metadata().dataStreams().size()));
        assertThat(
            newState.metadata().dataStreams().keySet(),
            containsInAnyOrder(cs.metadata().dataStreams().keySet().toArray(Strings.EMPTY_ARRAY))
        );
    }

    @SuppressWarnings("unchecked")
    private static MetadataDeleteIndexService getMetadataDeleteIndexService() {
        MetadataDeleteIndexService s = mock(MetadataDeleteIndexService.class);
        when(s.deleteIndices(any(ClusterState.class), any(Set.class))).thenAnswer(mockInvocation -> {
            ClusterState currentState = (ClusterState) mockInvocation.getArguments()[0];
            Set<Index> indices = (Set<Index>) mockInvocation.getArguments()[1];

            final Metadata.Builder b = Metadata.builder(currentState.metadata());
            for (Index index : indices) {
                b.remove(index.getName());
            }

            return ClusterState.builder(currentState).metadata(b.build()).build();
        });

        return s;
    }

    /**
     * Constructs {@code ClusterState} with the specified data streams and indices.
     *
     * @param dataStreams The names of the data streams to create with their respective number of backing indices
     * @param indexNames  The names of indices to create that do not back any data streams
     */
    public static ClusterState getClusterStateWithDataStreams(List<Tuple<String, Integer>> dataStreams, List<String> indexNames) {
        Metadata.Builder builder = Metadata.builder();

        List<IndexMetadata> allIndices = new ArrayList<>();
        for (Tuple<String, Integer> dsTuple : dataStreams) {
            List<IndexMetadata> backingIndices = new ArrayList<>();
            for (int backingIndexNumber = 1; backingIndexNumber <= dsTuple.v2(); backingIndexNumber++) {
                backingIndices.add(createIndexMetadata(DataStream.getDefaultBackingIndexName(dsTuple.v1(), backingIndexNumber), true));
            }
            allIndices.addAll(backingIndices);

            DataStream ds = new DataStream(
                dsTuple.v1(),
                createTimestampField("@timestamp"),
                backingIndices.stream().map(IndexMetadata::getIndex).collect(Collectors.toList()),
                dsTuple.v2()
            );
            builder.put(ds);
        }

        for (String indexName : indexNames) {
            allIndices.add(createIndexMetadata(indexName, false));
        }

        for (IndexMetadata index : allIndices) {
            builder.put(index, false);
        }

        return ClusterState.builder(new ClusterName("_name")).metadata(builder).build();
    }

    private static IndexMetadata createIndexMetadata(String name, boolean hidden) {
        Settings.Builder b = Settings.builder().put(IndexMetadata.SETTING_VERSION_CREATED, Version.CURRENT).put("index.hidden", hidden);

        return IndexMetadata.builder(name).settings(b).numberOfShards(1).numberOfReplicas(1).build();
    }
}
